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[E  CHEMICAL  COMPOSITION  OF  THE  OVARIES 

OF  THE 

FRESH  WATER  GAR,  LEPIDOSTEUS 


BY 

ERWIN  ELLIS  NELSON,  A.B.,  B.S.,  A.M., 
(with  Dr.  C.  W.  Greene) 


THESIS  SUBMITTED  IN  PARTIAL  FULFILMENT 
OF  THE  REQUIREMENTS  FOR  THE 

DEGREE  OF 
DOCTOR  OF  PHILOSOPHY 

IN  THE 
GRADUATE  SCHOOL 

OF  THE 

UNIVERSITY  OF  MISSOURI 
1920 


THE  CHEMICAL  COMPOSITION  OF  THE  OVARIES 

OF  THE 

FRESH  WATER  GAR,  LEPIDOSTEUS 


ERWIN  ELLIS  NELSON,  A.B.,  B.S.,  A.M., 
(With  Dr.  C.  W.  Greene) 


REPRINTED  FROM 

THE  JOURNAL  OF  BIOLOGICAL  CHEMISTRY 
VOL.  XLIX,  Xo.  1.  NOVEMBER,  1921 


Nf- 


Reprinted  from  THE  JOURNAL  OF  BIOLOGICAL  CHEMISTRY 
Vol.  XLIX,  No.  1,  November,  1921 


THE  CHEMICAL  COMPOSITION  OF  THE   OVARIES   OF 
FRESH  WATER  GAR,  LEPIDOSTEUS.* 

BY  ERWIN  E.  NELSON  t  AND  CHARLES  W.  GREENE. 

(From  the  Department  of  Physiology  and  Pharmacology,   Laboratory  of 
Physiology,  University  of  Missouri,  Columbia,  and  the  Biological 
Station  of  the  United  States  Bureau  of  Fisheries,  Fairport.) 

(Received  for  publication,  September  10,  1921.) 
INTRODUCTION. 

The  data  herein  reported  were  obtained  in  the  summer  of 
1917  as  a  part  of  the  results  of  a  study  of  fresh  water  fishery 
products  undertaken  with  a  view  to  extending  the  food  sources 
available  as  meat  substitutes.  Gar  eggs  are  of  similar  size  and 
color  to  sturgeon  eggs  and  have  been  unsuccessfully  used  as 
adultering  substitutes  for  sturgeon  eggs  for  caviar.  The  gar 
eggs  do  not  retain  their  color  in  caviar  processing  and  are  not 
pleasing,  in  fact  are  positively  objectionable,  in  flavor. 

Chemical  analyses  have  not  previously  been  reported  for  gar 
roe.  In  fact  there  is  a  dearth  of  analyses  of  either  roe  or  of  ovaries 
of  American  fishes.  Greene  (1921)  has  analyzed  the  ovaries 
of  the  king  salmon,  and  there  is  a  single  analysis  of  shad  roe  in 
Atwater's  paper  (1888.)  Greene  has  followed  the  development 
of  the  salmon  ovaries  which  occurs  during  the  spawning  migra- 
tion. There  is  a  great  increase  in  egg  mass  with  corresponding 
accumulation  of  protein  and  lipoids  in  the  egg  yolk,  of  which  he 
presents  evidence  to  show  is  derived  from  a  corresponding  storage 
in  the  muscles. 

*  Published  by  permission  of  the  United  States  Commissioner  of  Fish 
and  Fisheries. 

f  The  data  of  this  paper  were  used  in  part  in  the  dissertation  presented' 
by  Mr.  Erwin  E.  Nelson  for  the  degree  of  Doctor  of  Philosophy,  University 
of  Missouri,  1920. 

University  Fellow  in  the  Graduate  School,  University  of  Missouri, 
1916-18. 

47 


465863 


48  Ovaries  of  the  Gar,  Lepidosteus 

In  Europe  a  number  of  workers,  chiefly  German,  have  studied 
the  composition  of  roe  and  caviar.  The  earlier  literature  is 
given  in  Atwater's  monograph  on  the  food  fishes  of  America 
(1888).  More  recent  papers  are  those  of  Buttenberg  (1900-02), 
Rimini  (1904),  Farnstein  (1903-04),  Albu  and  Neuberg  (1906), 
and  Weitzel  (1916).  Tangl  and  Farkas  (1904)  followed  the  changes 
in  composition  of  the  fish  egg  with  development  of  the  embryo. 
Solberg  (1906)  analyzed  codfish  roe.  Konig  and  Grossfeld  (1913) 
made  a  very  complete  study  of  the  use  of  fish  roe  as  food,  taking 
up  in  considerable  detail  the  proteins,  fats,  and  extractives. 

Material  and  Methods. 

Our  samples  of  gar  ovary  were  obtained  from  twelve  specimens 
t)f  Lepidosteus  platystomus  and  one  sample  of  Lepidosteus  osseus. 
We  did  not  secure  samples  of  the  larger  southern  species,  the 
-alligator  gar,  Lepidosteus  tristoechus. 

The  method  followed  is  essentially  that  perfected  by  Janney 
(1916)  and  used  by  C.  H.  Greene  (1919)  in  his  study  of  the 
extractives  of  the  muscle  of  the  king  salmon.  The  samples  of 
tissue  for  analysis  were  in  all  cases  taken  fresh,  generally  while 
still  physiologically  alive.  Samples  of  the  ovaries  were  placed 
in  weighed  glass-stoppered  bottles,  weighed  at  once,  and  trans- 
ferred to  casseroles  and  extraction  with  hot  alcohol  was  begun  at 
once,  or  they  were  covered  with  95  per  cent  alcohol  and  sealed 
with  hard  .paraffin  for  transportation. 

Samples  for  the  determination  of  water  were  taken  at  the 
•same  time  and  weighed  at  once,  then  dried  to  constant  weight 
at  105°C.  Water  determinations  were  generally  made  in  duplicate. 

The  analysis  of  the  samples  was  carried  out  in  the  following 
manner:  the  sample  and  the  alcohol  covering  it  were  transferred 
quantitatively  to  a  porcelain  casserole  of  about  300  cc.  capacity. 
The  alcohol  was  brought  to  boiling  to  complete  the  coagulation 
of  the  proteins.  It  was  then  poured  off  into  a  wide  mouthed 
short  necked  flask,  and  placed  on  the  water  bath.  Subsequent 
alcohol  and  water  extracts  were  placed  in  this  flask,  which  was 
kept  on  the  water  bath.  If  the  sample  were  very  fat,  two  or 
three  preliminary  extractions  with  ether  were  made.  The  sample 
was  next  extracted  with  boiling  water  in  50  to  100  cc.  portions, 
at  least  eight  extractions  being  made.  The  residue  was  then 


E.  E.  Nelson  and  C.  W.  Greene  49 

washed  with  95  per  cent  alcohol  and  transferred  to  a  Gooch 
crucible.  The  crucible  was  placed  in  a  Greene's  (1909)  modified 
Soxhlet  apparatus  and  extracted  continuously  with  95  per  cent 
alcohol  for  12  hours.  This  was  followed  with  absolute  alcohol 
for  12  hours,  and  then  ether  for  from  18  to  24  hours.  After  the 
alcohol-ether  extraction  was  complete  the  residue  was  transferred 
to  a  weighing  vial,  dried  to  constant  weight  at  105°C.,  and  weighed. 
This  fraction  appears  in  the  tables  as  the  protein  residue. 

The  preliminary  ether  extract,  the  ether  from  the  Soxhlet,  and 
the  ether-soluble  material  obtained  from  the  alcohol-water  extracts 
as  described  below,  were  evaporated  and  dried  at  50° C.  and 
75  mm.  of  mercury  in  a  vacuum  oven.  The  oily  material  was 
dissolved  in  dry  ether,  filtered  into  weighing  vials,  and  dried 
to  constant  weight  in  the  vacuum  oven.  This  is  the  lipoid  frac- 
tion of  the  tables.  At  this  point  there  was  generally  a  small 
amount  of  material  which  was  insoluble  in  the  ether.  This  was 
dissolved  in  water  and  added  to  the  alcohol-water  extracts  as 
described  below. 

The  alcohol  and  water  extracts  were  combined  and  evaporated 
to  dryness  on  the  water  bath.  The  dry  residue  was  then  extracted 
with  ether,  and  the  ether-soluble  material  added  to  that  from  the 
preliminary  ether  extraction  and  the  Soxhlet  extraction  as  men- 
tioned in  the  preceding  paragraph.  The  residue  insoluble  in 
ether  was  taken  up  with  water  and  made  up  to  250  cc.  This 
solution  contains  the  extractives.  100  cc.  were  evaporated'  to 
dryness  in  a  platinum  shell,  weighed,  ashed,  and  weighed  again. 
The  water-soluble  solids,  and  the  ash  of  the  water-soluble  solids 
were  obtained  from  these  figures. 

Total  nitrogen  of  the  extractives  was  determined  in  an  aliquot 
by  Gulick's  modification  of  the  Folin-Farmer  colorimetric  method 
(1914). 

Creatine  was  determined  in  10  cc.  aliquots  by  dehydrolysis 
and  calculated  as  creatinine  (Folin,  1914).  The  10  cc.  samples 
were  evaporated  to  dryness  on  the  water  bath  with  10  cc.  of 
N  HC1  and  a  bit  of  metallic  lead,  and  the  residue  taken  up  quan- 
titatively with  hot  water  and  washed  into  a  25  cc.  volumetric 
flask.  10  cc.  of  saturated  picric  acid  and  1  cc.  of  10  per  cent 
NaOH  were  added,  the  mixture  was  cooled  at  the  tap,  and  allowed 
to  stand.  The  necessary  amount  of  standard  creatinine  solution 


50  Ovaries  of  the  Gar,  Lepidosteus 

was  placed  in  a  similar  flask  and  treated  with  NaOH  and  picric- 
acid  in  the  same  manner.  At  the  end  of  10  minutes  both  flasks 
were  filled  to  the  mark  with  distilled  water  and  the  readings 
taken  in  a  Duboscq  colorimeter.  All  determinations  were  made 
by  daylight.  The  standard  creatinine  was  isolated  from  urine 
by  Benedict's  method  (1914)  and  checked  against  a  sample  of 
pure  creatinine  from  Dr.  Myers'  laboratory.  The  values  as 
recorded  in  the  tables  of  this  paper  are  in  terms  of  creatine  ob- 
tained by  multiplying  the  creatinine  determination  by  the  factor 
1.16. 

The  amino  nitrogen  of  the  extractives  was  obtained  by  the 
method  of  Van  Slyke  (1912)  using  the  micro-apparatus.1 

Protocols  with  Descriptive  Data  for  Chemical  Samples. 

Sample  Cll. — Fish  18.  Lepidosteus  platystomus  ovary.  Length  of  fish 
52  cm.,  weight  385  gm.  Weight  of  ovaries  15.9  gm.,  diameter  of  ova  1.2  mm. 
Weight  of  chemical  sample  11.908  gm.  Fairport,  Iowa,  July  25,  1917. 

Sample  C20. — Fish  19.  Lepidosteus  platystomus  ovary.  Length  of  fish 
52  cm.,  weight  435  gm.  Weight  of  ovaries  30.5  gm.,  diameter  of  ova  varied 
to  a  marked  degree.  "Many  small  white  immature  ova."  Largest  ova 
2.2  mm.,  smallest  0.8  mm.  Weight  of  chemical  sample  18.464  gm.  Fair- 
port,  Iowa,  July  25,  1917. 

Sample  C22. — Fish  32.     Lepidosteus  platystomus  ovary.     Length  of  fish 

56.3  cm.,  weight  535  gm.     Weight  of  ovaries  48.3  gm.,  diameter  of  ova  1.7 
mm.    Weight  of  chemical  sample  17.858  gm.     New  Boston,  Illinois,  August 
25, 1917. 

Sample  C26. — Fish  29.  Lepidosteus  platystomus  ovary.  Ovary  weight 
27  gm.,  diameter  of  ova  1.5  mm.  "Ovary  filled  with  red  fat."  Weight  of 
chemical  sample  20.958  gm.  Fairport,  Iowa,  August  16,  1917. 

Sample  C29. — Fish  35.  Lepidosteus  platystomus  ovary.  Length  of  fish 
57.5  cm.,  weight  504  gm.  Weight  of  ovaries  48.5  gm.,  diameter  of  ova  1.9 
mm.  Weight  of  chemical  sample  20.808  gm.  New  Boston,  Illinois,  August 
25,  1917. 

Sample  C36. — Fish  33.  Lepidosteus  platystomus  ovary.  Length  of  fish 
58  cm.,  weight  611  gm.  Weight  of  ovaries  52.8  gm.,  diameter  of  ova  1.8 
mm.  Weight  of  chemical  sample  20.373  gm.  New  Boston,  Illinois,  August 
25,  1917. 

Sample  CSS. — Fish  34.     Lepidosteus  platystomus  ovary.     Length  of  fish 

55.4  cm.,  weight  619  gm.     Weight  of  ovaries  72.5  gm.,  diameter  of  ova 
2.0  mm.     Weight  of  chemical  sample  20.059  gm.     New  Boston,  Illinois, 
August  25,  1917. 

1  All  total  nitrogen  and  amino  nitrogen  determinations  were  made  f or- 
us  by  Mr.  Louis  Gambee. 


E.  E.  Nelson  and  C.  W.  Greene 


51 


Sample  41b. — Lepidosteus  platystomus  ovary.  Mixed  sample.  "In  salt, 
1  to  6.  Roe  immature,  full  of  fat."  Weight  of  chemical  sample  20.071 
gin.  Received  by  express  from  New  Boston,  Illinois,  September  26,  1917. 

Sample  ^a. — Lepidosteus  osseus  ovary.  Weight  of  sample  22.958  gm. 
Weight  of  ovary  estimated  500  gm.  Received  from  New  Boston,  Illinois, 
by  express  November  12,  1917. 

TABLE  I. 
Summary  of  Results  of  Analyses  of  Gar  Ovaries.* 


No. 

Lipoid. 

Pro- 
tein. 

Extractives. 

Water,  by 

Solids. 

Ash. 

Total 

N. 

Amino 

N. 

Creatine. 

Differ- 
ence. 

Determi- 
nation. 

Cll 

11.3 

15.7 

2.08 

0.56 

0.217 

0.056 

0.0101 

70.9 

72.9 

C20 

14.0 

23.8 

2.75 

0.49 

0.218 

0.049 

0.0111 

59.4 

57.1 

C22 

12.4 

26.3 

1.13 

0.31 

0.291 

0.028 

| 

60.1 

61.0 

C26 

20.  6f 

23.3 

1.27 

0.28 

0.130 

0.038 

0.0069 

61.5 

56.2 

C29 

17.4 

25.6 

1.09 

0.27 

0.077 

0.023 

0.0085 

55.8 

57.0 

C36 

14.4 

27.9 

1.21 

0.54 

0.074 

0.017 

0.0051 

56.4 

57.1 

C38 

17.9 

24.8 

1.21 

0.25 

0.076 

0.044 

0.0080 

56.0 

56.4 

41a 

14.0 

26.4 

18.45 

14.66 

0.243 

0.031 

0.0082 

41.1 

t 

41b 

12.8 

26.7 

17.16 

10.82 

0.229 

0.036 

0.0097 

43.3 

1 

42a 

26.9 

28.4 

0.79 

0.25 

0.053 

0.020 

Trace. 

43.9 

i 

C63 

17.3 

26.3 

1.15 

0.51 

0.091 

0.015 

$ 

55.2 

l 

C66 

17.6 

25.3 

1.02 

0.38 

0.072 

Trace. 

+ 
+ 

56.0 

t 

C78 

18.3 

26.2 

1.54 

0.56 

0.138 

0.006 

1 

54.0 

i 

*  No.  42a  is  from  Lepidosteus  osseus,  the  remainder  are  Lepidosteus 
platystomus.  All  calculations  are  in  terms  of  parts  per  100  gm.  of  moist 
sample. 

t  Part  lost. 

I  Not  determined. 

Sample  C6S. — Lepidosteus  platystomus  ovary.  Length  of  fish  61  cm., 
weight  of  ovary  66.7  gm.  Weight  of  chemical  sample  24.095  gm.  Hanni- 
bal, Missouri,  July  30,  1920. 

Sample  C66. — Lepidosteus  platystomus  ovary.  Length  of  fish  58.5  cm., 
weight  of  ovary  91.65  gm.  Weight  of  chemical  sample  27.46  gm.  Hanni- 
bal, Missouri,  July  30,  1920. 

Sample  C78. — Lepidosteus  platystomus  ovary.  Length  of  fish  55.8  cm., 
weight  of  ovary  94.75  gm.  Weight  of  chemical  sample  28.28  gm.  Hanni- 
bal, Missouri,  July  30,  1920. 


52 


Ovaries  of  the  Gar,  Lepidosteus 


DISCUSSION. 

Lipoids. 

The  lipoid  fraction  in  terms  of  the  moist  sample  of  ovary  is 
comparatively  large,  from  15  to  20  per  cent.  In  the  single  sample 
of  Lepidosteus  osseus,  42a,  it  reaches  26  per  cent,  which  is  higher 
than  any  value  for  fish  ovary  found  in  the  literature.  In  the  gar 
ovary,  especially  in  the  young  stages,  there  is  a  deposit  of  fat  in 
the  supporting  tissues  which  in  some  samples  is  quite  considerable. 

TABLE  II. 
Analyses  Arranged  in  Series  According  to  the  Weights  of  the  Ovaries. 


No. 

Weight 
of  ovary. 

Diameter 
of  ova. 

Length 
of  fish. 

Lipoid. 

Protein. 

Extrac- 
tives. 

Water. 

gm. 

mm. 

cm. 

Cll 

15.9 

1.2 

38.5 

11.3 

15.7 

2.07 

72.9 

C26 

27.0 

1.5 

* 

20.  6f 

23.3 

1.26 

56.2 

C20 

30.5 

2.2  to  0.8 

43.5 

14.0 

23.8 

2.70 

57.0 

C22 

48.0 

1.7 

53.5 

12.4 

26.3 

1.13 

61.0 

C29 

48.5 

1.9 

60.4 

17.4 

25.6 

1.09 

57.0 

C36 

52.0 

1.8 

61.1 

14.4 

27.8 

1.20 

57.1 

C63 

66.7 

* 

61.0 

17.3 

26.3 

1.15 

53.1 

C38 

72.0 

2.0 

61.9 

17.9 

24.8 

1.21 

56.4 

C66 

91.6 

* 

58.5 

17.6 

25.3 

1.03 

56.0 

C78 

94.7 

* 

55.8 

18.3 

26.2 

1.54 

53.9 

42a 

J 

t 

{ 

26.9 

28.4 

0.79 

43.9 

*  Not  recorded. 

f  The  notes  record  that  there  was  a  large  amount  of  extra-ovular  fat 
in  this  ovary 

J  Not  recorded,  but  this  was  undoubtedly  the  oldest  fish  of  the  series. 
The  ovary  weighed  several  hundred  grams. 

The  analysis  of  the  entire  ovary  does  not  distinguish  between  this 
fat,  which  might  be  called  extra-ovular,  and  the  lipoids  of  the 
developing  ovules  with  their  increasing  mass  of  cell  yolk.  The 
total  egg  yolk  lipoids  seem  to  increase  as  the  eggs  develop. 

If  one  arranges  the  analyses  in  a  series  according  to  the  weight 
of  the  ovaries,  it  is  noted  that  in  a  general  way  the  percentage 
of  ether-soluble  materials  increases  with  the  increase  in  weight, 
Table  II.  The  parallelism  between  increase  in  weight,  diameter 
of  the  ova,  and  length  of  the  fish  shown  in  this  table  is  evidence 
that  the  increase  in  lipoids  is  in  part  at  least  due  to  growth  of 


E.  E.  Nelson  and  C.  W.  Greene  53 

the  ovary,  and  not  to  the  accumulation  of  extra-ovular  fat.  The 
weight  of  the  ovary  is  a  fair  criterion  of  the  age  of  the  ovary. 
Because  of  the  inability  to  differentiate  between  the  source  of 
the  various  lipoid  fractions,  it  would  seem  that  a  more  accurate 
picture  of  the  metabolic  changes  might  be  gained  by  calculating 
the  data  on  a  fat-free  basis.  This  has  been  done  in  Table  III. 

Proteins. 

There  is  a  rather  close  approximation  in  the  values  for  the 
proteins,  if  Sample  Cll  and  the  single  sample  of  Lepidosteus 
osseus,  42a,  be  disregarded.  Cll  is  a  very  much  younger  fish, 
if  one  may  judge  by  the  weight  of  the  ovaries  and  the  diameter 
of  the  ova.  Greene  (1918)  showed  for  the  salmon  that  the  pro- 
tein content  of  the  ovary  was  remarkably  constant  throughout 
the  period  of  late  development.  Sample  Cll  is  an  interesting 
case  of  an  ovary  which  has  not  yet  reached  the  average  protein 
content  for  the  species.  Its  water  content  is  the  highest  of  all 
the  specimens  examined.  Sample  42a  is  obviously  a  much  more 
mature  specimen.  It  has  the  highest  protein,  28.4  per  cent, 
and  the  lowest  water,  43.9  per  cent,  content  of  all  the  ovaries 
studied.  This  might  be  explained  on  the  grounds  of  the  difference 
in  species.  But  Hatai  (1917)  has  shown  that  in  the  white  rat 
there  is  an  increase  in  protein  and. a  decrease  in  water  content  of 
the  whole  body  throughout  the  whole  growth  period.  These 
facts,  especially  when  taken  in  conjunction  with  the  variations 
in  the  extractive  fractions,  argue  for  a  more  active  stage  of  me- 
tabolism in  the  early  growth  period  of  the  gar  ovaries. 

The  average  values  for  protein  are  in  close  agreement  with 
those  found  by  Greene  (1918)  for  the  salmon.  They  also  agree 
closely  with  unpublished  data  for  the  ovaries  of  the  carp. 

Organic  Extractives. 

The  organic  extractives  present  in  the  tissue  waters  of  all  ani- 
mal organs  are  an  indirect  measure  of  the  metabolic  processes 
in  the  individual  tissue.  Hatai  (1917)  has  shown  that  the  tis- 
sues of  the  growing  white  rat  contain  a  greater  proportion  of 
extractives  than  those  of  the  adult.  During  the  migration  of  the 
king  salmon  Greene  (1918)  showed  that  the  organic  extractives 


54  Ovaries  of  the  Gar,  Lepidosteus 

of  the  muscle  at  first  increase  slightly,  then  remain  comparatively 
constant  in  proportion  to  the  tissue  waters  until  late  in  the  spawn- 
ing. At  the  spawning  when  the  animals  are  approaching  death 
by  inanition  the  tissue  waters  are  less  saturated.  In  the  devel- 
oping ovaries  the  organic  extractives  are  of  a  much  lower  con- 
centration than  in  the  muscles.  The  percentage  does  not  vary 
much  during  the  entire  migration.  C.  H.  Greene  (1919)  found 
with  respect  to  the  muscular  tissue  that  while  the  absolute  amount 
of  protein  decreases,  the  organic  extractives,  especially  the  amino 
nitrogen,  remain  constant  or  increase  in  spite  of  the  fact  that  the 
protein  from  which  they  are  derived  is  constantly  decreasing. 
The  lower  concentration  in  the  ovaries  would  seem  to  be  a  func- 
tion of  the  anabolic  processes  whereby  the  ovarian  extractives 
are  being  synthesized  into  proteins.  At  any  rate  the  gar  muscle 
extractives  average  about  2.5  per  cent  while  the  extractives  of 
the  ovaries  average  about  1  per  cent. 

If  the  ratio  of  organic  extractives  to  protein  be  figured  for  the 
series  given  in  Table  II,  it  will  be  seen  that  the  extractives  exist 
in  the  largest  ratio  in  the  youngest  ovary,  Cll  (Table  III).  In 
C20,  which  contained  a  large  number  of  small  immature  ova,  the 
ratio  is  also  1 : 10.  In  42a,  which  was  certainly  the  oldest 
specimen,  the  ratio  is  the  smallest,  1 :  52.  The  other  ratios  vary 
in  no  regular  order  from  1 : 24  to  1 : 42.  In  the  case  of  the  amino 
nitrogen,  the  amounts  are  again  certainly  greatest  in  the  young- 
est specimens,  decreasing  with  maturity. 

In  general  there  is  a  good  deal  of  variation  in  the  figures  for  the 
fractions  of  the  organic  extractives;  viz.,  total  nitrogen,  amino 
nitrogen,  and  creatine.  In  view  of  the  relation  between  amino 
nitrogen  recently  pointed  out  by  C.  H.  Greene  (1919)  it  is  of 
interest  to  note  that  the  sample  having  the  highest  water  content, 
Cll,  has  also  the  highest  value  for  amino  nitrogen,  and  that  the 
one  with  the  lowest  water,  42a,  gave  with  one  exception  the  lowest 
value  for  amino  nitrogen.  The  low  value  for  C36  is  not  explained. 

Konig  and  Grossfeld  (1913)  have  studied  the  composition 
of  the  extractives  of  fish  eggs,  and  have  isolated  xanthine,  hypo- 
xanthme,  creatinine,  taurine,  and  tyrosine.  In  view  of  the  ease 
with  which  creatine  is  changed  to  creatinine  in  the  manipulations 
of  the  analysis,  Grindley  and  Woods  (1906),  it  would  seem  doubt- 
ful whether  there  is  really  any  preformed  creatinine  in  fish  eggs. 


E.  E.  Nelson  and  C.  W.  Greene 


55 


Creatine  was  found  in  gar  eggs  in  amounts  varying  from  traces 
up  to  slightly  less  than  10  mg.  per  100  gm.  of  moist  sample.  No 
especial  significance  is  attached  to  this  observation. 

The  Inorganic  Ash  and  Water. 

Our  data  show  variations  of  the  ash  from  0.25  to  0.59  per  cent, 
a  rather  extreme  variation,  for  which  there  is  no  obvious  explanation. 

Water  determinations  were  made  directly  on  separate  samples 
of  the  first  seven  fish  but  only  indirectly  on  the  others.  The 

TABLE  III. 

The  Protein,  Water,  and  Extractive  Fractions  Figured  on  a  Fat-Free  Basis, 
and  Arranged  in  Series  According  to  the  Weights  of  the  Ovaries. 


No. 

Weight  of 
ovary. 

Protein. 

Organic 
extrac- 
tives.* 

Ratio 
protein: 
extractives. 

Total  N. 

Amino  N. 

Water. 

Cll 

15.9 

17.7 

1.70 

10:1 

0.244 

0.063 

79.9 

C26 

27.0 

29.4 

1.24 

24:1 

0.164 

0.048 

69.1 

C20 

30.5 

27.7 

2.63 

10:1 

0.254 

0.057 

69.1 

C22 

48.0 

30.0 

0.94 

32:1 

0.332 

0.031 

68.7 

C29 

48.5 

31.0 

1.00 

31:1 

0.092 

0.027 

67.6 

C36 

52.0 

32.6 

0.78 

42:1 

0.086 

0.020 

66.0 

C63 

66.7 

31.8 

0.66 

48:1 

0.111 

0.018 

64.6 

C38 

72.0 

30.2 

1.18 

27:1 

0.093 

0.054 

68.4 

C66 

91.6 

30.8 

0.79 

35:1 

0.088 

Traces. 

70.8 

C78 

94.7 

32.0 

1.19 

27:1 

0.168 

0.007 

66.0 

42a 

t 

38.9 

0.74 

52:1 

0.073 

0.028 

60.0 

*  The  organic  extractives  were  obtained  by  subtracting  the  ash  from 
the  water-soluble  solids. 

f  Not  recorded,  but  the  weight  was  several  hundred  grams. 

water  determination  by  differences  throws  the  cumulative  error 
on  this  fraction.  Nevertheless,  the  agreement  is  quite  close  as 
between  the  indirect  and  the  direct  determinations  on  the  first 
seven  specimens. 

General  Comparison. 

We  hoped  to  be  able  to  compare  the  composition  of  the  gar  ovaries 
at  different  stages  of  development.  However,  these  fish  apparently 
spawn  over  a  long  season  and  there  is  no  way  of  determining  the 
degree  of  development  except  by  the  general  appearance  and  the 
variation  in  size  of  the  ovules.  In  our  youngest  specimen,  Cll, 


56  Ovaries  of  the  Gar,  Lepidosteus 

the  diameter  is  1.2  mm.  In  C20,  there  was  the  greatest  varia- 
tion. A  few  ova  were  as  small  as  0.8  mm.,  while  others  were  as 
much  as  2.2  mm.  in  diameter.  2  mm.  is  the  average  diameter 
of  the  adult  egg.  In  one  very  large  fish,  No.  42a,  the  total  weight 
of  the  ovaries  was  estimated  at  500  or  600  gm.  These  were  the 
most  mature  in  appearance  of  any  collected.  This  ovary  had  a 
lower  water  content,  the  highest  protein  content,  and  a  much 
higher  amount  of  total  fats.  Broadly  speaking,  the  protein 
except  in  the  very  young  remains  comparatively  constant.  The 
organic  extractives  are  also  constant.  The  total  lipoids  tend  to 
increase  and  the  total  water  to  decrease  with  development  of 
the  gar  ovaries. 
We  were  not  successful  in  securing  ripe  ova  for  analysis. 

BIBLIOGRAPHY. 

Albu,  A.,  and  Neuberg,  C.,  Physiologic  der  Mineralstoffwechsels,  Berlin, 
1906. 

Atwater,  W.  O.,  Rep.  U.  S.  Com.  Fish  and  Fisheries,  1888,  679. 

Benedict,  S.  R.,  J.  Biol.  Chem.,  1914,  xviii,  183. 

Buttenberg,  P.,  Bericht  des  Hygien.  Instituts  Hamburg,  1900-02,  13; 
abstracted  in  Z.  Untersuch.  Nahrungs-  u.  Genussmittel. ,  1904,  vii,  233. 

Farnstein,  K,  Lendrick,  H.,  Buttenberg,  P.,  Kickton,  A.,  andKlassert,  M., 
Bericht  der  Nahrungsmittelkontrolle,  Hamburg,  1903-04;  abstracted 
in  Z.  Untersuch.  Nahrungs-  u.  Genussmittel.,  1906,  xi,  742. 

Folin,  O.,  J.  Biol.  Chem.,  1914,  xvii,  469. 

Greene,  C.  H.,  J.  Biol.  Chem.,  1918,  xxxiii,  p.  xii. 

Greene,  C.  H.,  J.  Biol.  Chem.,  1919,  xxxix,  457. 

Greene,  C.  W.,  J.  Biol.  Chem.,  1909,  vii,  503. 

Greene,  C.  W.,  J.  Biol.  Chem.,  1918,  xxxiii,  p.  xiii. 

Greene,  C.  W.,  /.  Biol.  Chem.,  1921,  xlviii,  59. 

Grindley,  H.  S.,  and  Woods,  H.  S.,  J.  Biol.  Chem.,  1906,  ii,  309. 

Gulick,  A.,  /.  Biol.  Chem.,  1914,  xviii,  541. 

Hatai,  S.,  Am.  J.  Anat.,  1917,  xxi,  23. 

Janney,  N.  W.,  /.  Biol.  Chem.,  1916,  xxv,  177. 

Konig,  J.,  and  Grossfeld,  J.,  Biochem.  Z.,  1913,  liv,  351. 

Rimini,  E.,  Z.  Untersuch.  Nahrungs-  u.  Genussmittel.,  1904,  vii,  232. 

Solberg,  E.,  Bericht  der  Norwegischen  Landwirtschaftlichen  Kontroll- 
station  Trondheim  fur  1906,  Christiania,  1907;  abstracted  in  Z.  Unter- 
such. Nahrungs-  u.  Genussmittel.,  1908,  xvi,  364. 

Tangl,  F.,  and  Farkas,  K.,  Arch.  ges.  PhysioL,  1904,  civ,  624. 

Van  Slyke,  D.  D.,  J.  Biol.  Chem.,  1912,  xii,  275. 

Weitzel,  A.,  Arb.  k.  Gsndhtsamte,  1916,  1,  361;  abstracted  in  Z.  Untersuch. 
Nahrungs-  u.  Genussmittel.,  1918,  xxxvi,  171. 


Vita. 

I,  ERWIN  ELLIS  NELSON,  was  born  June  11,  1891,  in  Spring- 
field, Missouri,  the  first  child  of  my  parents,  Harry  Anderson 
Nelson  and  Jennie  Ellis  Nelson.  I  received  my  early  education 
in  Springfield,  graduating  from  the  Springfield  High  School  in 
1909.  The  same  year  I  entered  Drury  College,  where  I  was  a 
student  until  1912,  taking  the  premedical  group  of  studies.  The 
following  year  I  was  Instructor  in  Science  in  the  Southern  Col- 
legiate Institute  at  Albion,  Illinois.  In  1913  I  entered  the  Uni- 
versity of  Missouri  as  a  senior  in  the  College  of  Arts  and  a  first 
year  student  in  the  School  of  Medicine.  I  received  the  degree  of 
Bachelor  of  Arts  from  the  University  of  Missouri  in  1914  and  in 
the  same  year  the  degree  of  Bachelor  of  Science  from  Drury 
College.  In  February  1914  I  was  appointed  Assistant  in  Zoology 
in  the  University  of  Missouri,  which  position  I  held  until  June 
1916.  From  1914  to  1918  I  was  enrolled  in  the  Graduate  School 
of  the  University  of  Missouri,  and  for  most  of  this  time  also  in 
the  School  of  Medicine.  I  was  granted  the  degree  of  Master  of 
Arts  in  1916,  my  major  being  Zoology.  From  1916  to  1918  I  was 
University  Fellow  in  Physiology,  resigning  in  the  second  semester 
to  become  Assistant  in  Physiology.  During  the  year  1918-19 1  was 
a  junior  in  Johns  Hopkins  Medical  School.  In  1919  I  was  ap- 
pointed Assistant  Professor  of  Pharmacology  in  the  University 
of  Michigan  School  of  Medicine,  which  position  I  now  hold.  In 
1920  I  passed  the  examinations  for  the  degree  of  Doctor  of  Phi- 
losophy at  the  University  of  Missouri. 


Gaylord  Bros. 

Makers 

Syracuse,  N.  V. 
"PAT.  JAN.  21 ,1908 


The   ch 
.tion  o 

the   fresh 


el   cornpo- 
e  ovarl* 
water  gar 


84 

HOLOGY 
LIBRARY 


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